Mechanical locks based on mechanical types of cylinders have been frequently modified by the addition of electronic security features. Locking elements controlled by electronic-means have been disclosed in combination with non-mechanical types of tumblers, such as in Clarkson et al. U.S. Pat. No. 4,712,398 with an eye to reduce the need to retrofit the traditional locks.
The use of electronic techniques for coding locks offers the possibility of a number of significant advantages as compared with the traditional mechanical bitting. Electronic coding can increase information content with attendant improvements to system capabilities such as more effective new countermeasures against “lock-picking” attempts.
A distinction may be made among purely electronic, magnetic or optical keys; mechanical keys equipped with electronic, magnetic or optical features; and mechanical keys which operate solely by mechanical bittings, whether those bittings be pin tumbler, dimples or other mechanical patterns.
A key comprised of electronic circuitry, magnetic or optical data storage for determining and granting access is an electronic key assembly. Some examples are described in U.S. Pat. No. 3,733,862 (Killmeyer), U.S. Pat. No. 4,144,523 (Kaplit), U.S. Pat. No. 4,326,124 (Faude), U.S. Pat. No. 4,562,712 (Wolter), U.S. Pat. No. 4,663,952 (Gelhard), U.S. Pat. No. 4,686,358 (Seckinger et al.), U.S. Pat. No. 5,245,329 (Gokcebay) and U.S. Pat. No. 5,140,317 (Hyatt, Jr. et al.). For unlocking a lock, using such a key, data is transferred to a reader associated with a lock, and the reader, in response to recognizing the pattern or code held by the key, activates unlocking. The key, see e.g., U.S. Pat. No. 3,797,936 (Dimitriadis), U.S. Pat. No. 4,209,782 (Donath et al.), U.S. Pat. No. 4,257,030 (Bruhin et al.), U.S. Pat. No. 4,620,088 (Flies), U.S. Pat. No. 4,659,915 (Flies) and U.S. Pat. No. 4,789,859 (Clarkson et al.), does require any mechanical cut or bitting configurations.
Mechanical keys, see, e.g., U.S. Pat. No. 480,299 (Voight), U.S. Pat. No. 550,111 (Sargent), U.S. Pat. No. 564,029 (Sargent), U.S. Pat. No. 3,208,248 (Tornoe), U.S. Pat. No. 4,723,427 (Oliver), U.S. Pat. No. 4,732,022 (Oliver) and U.S. Pat. No. 4,823,575 (Florian et al.), directly activate a mechanical device, with a pattern of mechanical bittings, by direct contact with the interpreting device, for instance, the tumblers, such as pin tumblers, lever tumblers, disk tumblers, rotary disk tumblers, slider tumblers, or combinations of several of these incorporated within the same lock, or other pattern-holding apparatus contained in the lock. Typically, access is granted based on the depth and configuration of the key cuts relative to the tumblers, and the keyholder is able to turn the key to lock and unlock the locking device. As a variation, a push or pull action may also be necessary for locking and unlocking. In some instances both mechanical and non-mechanical features of a key are used simultaneously.
Electronic locks and keys are often found in remotely operated devices such as car locks, garage openers and the like. However, each of these remotely operated locks require their own physical key, which typically may be bulkier than the mechanical keys. It is not uncommon to have several such keys, also termed remotes, in combination with mechanical keys. Misplacing or losing such a key is easy while duplicating them continues to be both difficult and expensive.
An example of an electronic lock and key system is the E-Lock™ product marketed by Lista® corporation of Switzerland. While the E-Lock system allows a single key to operate several electronic locks, the keys are designed to be copy proof. Loss or pilfering of a key is handled by reprogramming the system and using a new key corresponding to the reprogrammed setup. In addition, the electronic locks may be configured to relock themselves after a certain amount to further improve security.
Other examples of electronic lock and key systems include the DATAKEY CIP™ smart card. The smart card has the capability of generating keys or of receiving keys generated elsewhere. TRACcess® provides another system of electronic locks, which are operated with an authorized TRACkey™ and is configured to track all activity without relying upon external power or phone lines. The TRACcess® is a large entity solution to provide integrated security that is not suitable for day to day use by individual consumers.